Toward 200 Lumens per Watt of Quantum-Dot White-Light-Emitting Diodes by Reducing Reabsorption Loss

Jia-Sheng Li, Yong Tang, Zong-Tao Li*, Jie-Xin Li, Xin-Rui Ding, Bin-Hai Yu, Shu-Dong Yu, Jian-Zhen Ou, Hao-Chung Kuo

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

In this study, we analyze the influence of the pore structure of an SBA-15 particle on the light emission from its inner adsorbed quantum dots (QDs) and outer light-emitting diode (LED) chips. It is found that the particle features of a high refractive index, comparable feature size of pore structure, and lower amount of QD adsorption help with QD light extraction, demonstrating a mechanism to suppress QD light propagating through pores and thus reducing the reabsorption loss. We consequently developed highly efficient QD white LEDs with wet-mixing QD/SBA-15 nanocomposite particles (NPs) by further optimizing the packaging methods and the introduced NP mass ratio. The LEDs demonstrated a record luminous efficacy (the ratio of luminous flux to electrical power) of 206.8 (entrusted test efficiency of 205.8 lm W certificated by China National Accreditation Service) and 137.6 lm W-1 at 20 mA for white LEDs integrating only green QDs and green-red QD color convertors, respectively, with improved operating stability. These results are comparable to conventional phosphor-based white LEDs, which can be a starting point for white LEDs only using QDs as convertors toward commercialization in the near future.

Original languageEnglish
Pages (from-to)550-562
Number of pages13
JournalACS Nano
Volume15
Issue number1
DOIs
StatePublished - 26 Jan 2021

Keywords

  • quantum dot
  • light-emitting diode
  • luminous efficacy
  • reabsorption
  • wide-color gamut

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